3850 STACK

[denilson.mota]

Hi experts,

I have four brand news C3850-24T and I connect all data and power stacks but I see in switch 3 port 1 and switch 4 port 2 down but all cables are connect correct. Anyone can help to figure out why it shows down?

Switch# Role Mac Address Priority Version State
------------------------------------------------------------
*1 Active cc5a.5385.5d80 1 V07 Ready
2 Member ec1d.8b19.e500 1 V07 Ready
3 Member ec1d.8b11.7280 1 V07 Ready
4 Standby ec1d.8b19.6180 1 V07 Ready

Stack Port Status Neighbors
Switch# Port 1 Port 2 Port 1 Port 2
--------------------------------------------------------
1 OK OK 2 4
2 OK OK 3 1
3 DOWN OK None 2
4 OK DOWN 1 None

Thank you,

[smfahadzaidi]

you sure you have plugged-in cable as shown in figure

[Mark Malone]

If its not the cabling which it usually is maybe try enable the stack ports in case there shut them down

i.e
switch 1 stack port 2 enable
switch 2 stack port 1 enable

[denilson.mota]

Cable are connected and ports enable now seems OK but my problem is stack power redundancy as when I remove power cable from the other tree switches only the primary and two members remains UP the other goes down with back leds ON. The primary switch as two power supply 350W connected to have enough power to share with others if I remove one of the power supply the other switch goes down. How can I mange the stack power from all four switches?

[denilson.mota]

Please see the bellow error:

*Feb 22 11:55:11.758: %PLATFORM_STACKPOWER-4-UNBALANCED_PS: Switch 1's power stack has unbalanced power supplies
*Feb 22 11:55:11.759: %PLATFORM_STACKPOWER-4-INSUFFICIENT_PWR: Switch 1's power stack does not have enough power

[Mark Malone]

the power stack cables are in a full ring formation too yes ?
its also in power sharing mode and these are non poe switches yes ?

In power-sharing mode (the default), all input power is available to be used for power loads. The total available power in all switches in the power stack (up to four) is treated as a single large power supply, with power available to all switches and to all powered devices connected to PoE ports. In this mode, the total available power is used for power budgeting decisions and no power is reserved to accommodate power-supply failures. If a power supply fails, powered devices and switches could be shut down (load shedding).